Biology Semester II

Sections:

Introduction |  Section 1 | Section 2 | Section 3

Section Two:

Part 1 | Part 2 | Part 3 | Part 4 | Part 5 | Part 6 | Part 7 | Part 8 | Part 9

Biology: Flowering Plant Reproduction: Part Nine Vegetative Propagation All of us, without exception, were produced by the sexual reproduction of two adults—our parents. That is the way most animals reproduce: two individuals go through sexual reproduction to produce a new genetic entity—you. Plants have a variety of sexual reproduction methods, with flowers being the method highlighted in this part of the unit. Unlike animals, many plants also have an asexual method of reproduction. This allows plants to rapidly propagate and cover open areas. Plants have a variety of asexual means of propagating. Some species, such as many orchids, are more frequently propagated vegetatively than via seeds. Tubers are fleshy underground stems, as in the Irish potato. (The potato eyes are really buds on the stem, or in this case, the tuber.) Leaflets are sections of leaves that will develop roots and drop off the plant, effectively cloning the plant. Kalanchoe, the walking fern, produces a new plant where leaf tips touch the ground. In the greenhouse, small walking ferns will pop up in all sorts of areas! Kalanchoe, showing plantlets forming on the edge of the leaves. Potatoes showing the germination of the “eyes." Runners are shoots growing along or over the surface of the ground that will sprout a plantlet, which upon settling to the ground develop into a new independent plant. Strawberries propagate by this method. Rhizomes are underground stems that can produce new plants at each node. Grasses and irises propagate this way. Roots produce suckers that sprout and produce new plants. Commercial bananas are seedless, but are propagated by planting suckers. Near Salt Lake City, Utah, there is a six thousand acre stand of 47,000 aspen trees. Genetic analysis has shown that every tree is identical and suggests that the stand must have formed by the trees arising from roots. When new adult plants can be grown from single cells, clones result. Cells divide in the laboratory to produce a callus. When this is transplanted to a natural growth medium the calluses form mature plants. Forests of trees that become harvestable at the same time are a possible application of this phenomenon. Practice what you've learned in this interactive. Flowering Plant Reproduction Quiz 25 points Congratulations on completing this section! In this section, you learned about: Flowering Plant Life Cycles Flower Structure Pollen and Pollination “Double Fertilization” Seeds and Fruits Vegetative Propagation Now it’s time to take the section quiz. Please make sure to check your understanding of the topics above before proceeding to the quiz. After you have completed the quiz, continue with the unit. Now go on to the next section.

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